Generic pipe degradation in reactor safety systems in France spells more economic trouble for EdF and maybe for U.S. reactors

On October 11, 2017, the French Nuclear Safety Authority (ASN) issued an alert to the country’s nuclear industry for generically “degraded” pipes in critical pumping stations at twenty of Électricité de France’s (EdF) 58 atomic reactors. EdF is Europe’s largest builder and operator of nuclear power generators. That number has risen with the discovery of significant pipe corrosion “deviations"in nine more French nuclear power plants. The severely corroded pipes could potentially rupture in the event of an earthquake that the plant was originally designed to withstand but now might result in a complete or partial loss of reactor safety system cooling. The corrosion has also severely thinned the walls of pipes that supply water for the reactor sites' firefighting systems.

EdF is shutting down the country’s reactors to undergo “reinforcement” with carbon fiber wraps around the degraded pipes rather than the costly pipe replacement for the French state-owned utility already deep in debt. Nine of the 20 reactor units have completed the reinforcement of reactor cooling and firefighting pipe systems. Five more units are currently shut down where reinforcement repair is in progress. EdF reports that six units have applied the carbon fiber wrap around one of the two redundant cooling and firefighting pipe systems to reduce operational risks while work is underway on the backup piping systems.  

The finding of generic corrosion in French pressurized water reactor cooling and firefighting piping systems raises questions about those same systems in U.S. pressurized water reactors.  France’s nuclear fleet was rapidly ramped up based on the U.S. Westinghouse pressurized water reactor design initially for its Bugey and Fessenheim nuclear power stations. The fact that generic designs spawn generic problems now raises Beyond Nuclear concern that an investigation of the vulnerability to the same generic corrosion event in the U.S. Westinghouse design for pressurized water reactors is necessary.